Adaptive image display characteristics

ABSTRACT

Learning methods and systems are provided for predictive medical image calibration. In various embodiments, a request is received from a user for an image. One or more characteristic of the image is determined. One or more characteristic of the user is determined. A generalized linear model is applied to the one or more characteristic of the image and the one or more characteristic of the user to determine one or more image transformation. The one or more image transformation is applied to the image. The generalized linear model is updated based on any user-applied image transformations.

BACKGROUND

Embodiments of the present invention relate to automatically adaptingimage display characteristics, and more specifically, to learningmethods and systems for predictive medical image calibration.

BRIEF SUMMARY

According to embodiments of the present disclosure, methods of andcomputer program products for adapting image display characteristics areprovided. In some embodiments, a request is received from a user for animage. One or more characteristic of the image is determined. One ormore characteristic of the user is determined. A generalized linearmodel is applied to the one or more characteristic of the image and theone or more characteristic of the user to determine one or more imagetransformation. The one or more image transformation is applied to theimage. The generalized linear model is updated based on any user-appliedimage transformations.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 depicts an exemplary Picture Archiving and Communication System.

FIG. 2 illustrates an exemplary clinical image search and retrievalmethod.

FIG. 3 illustrates a method of adapting image display characteristicsaccording to embodiments of the present disclosure.

FIG. 4 depicts a computing node according to an embodiment of thepresent disclosure.

DETAILED DESCRIPTION

In medical imaging, the adjustment of window/level parameters iscritical to user interpretation of raw imagery. However, theseparameters are often adjusted on the fly, without a systematic approach,which potentially leads to missed features in complicated imagery.

To address this and other shortcomings of the prior art, a learning toolis provided for window/level and other image parameters. A user'spreferences are gathered and correlated against the characteristics ofthe images viewed to arrive at automated image adjustments. In addition,automated image adjustments may be based on feature extraction from theunderlying image.

When a user views a medical image, for example from a PACS system, theyadjust image display parameters such as window/level. According tovarious embodiments, the window/level settings are saved along withmetadata regarding the image and data regarding image characteristics.For example, an indication of the anatomy imaged may be stored alongwith a pixel intensity histogram. Based on a given user's history,preferences are determined. As future images are displayed, thepreferred window/level settings are loaded based on the identity of theviewer, the image characteristics, and the particular anatomy imaged.For example, a given doctor may prefer a typical window level for thelungs that is lower than that for the abdomen.

In addition, in various embodiments, after automated feature extractionfrom the image, window/level can be set on the basis of that feature.For example, if an area of interest is detected, the window/level may bepreset to give high contrast within the area of interest, rather thanover the whole of the image.

A Picture Archiving and Communication System (PACS) is a medical imagingsystem that provides storage and access to images from multiplemodalities. In many healthcare environments, electronic images andreports are transmitted digitally via PACS, thus eliminating the need tomanually file, retrieve, or transport film jackets. A standard formatfor PACS image storage and transfer is DICOM (Digital Imaging andCommunications in Medicine). Non-image data, such as scanned documents,may be incorporated using various standard formats such as PDF (PortableDocument Format) encapsulated in DICOM.

Referring to FIG. 1, an exemplary PACS 100 consists of four majorcomponents. Various imaging modalities 101 . . . 109 such as computedtomography (CT) 101, magnetic resonance imaging (MM) 102, or ultrasound(US) 103 provide imagery to the system. In some implementations, imageryis transmitted to a PACS Gateway 111, before being stored in archive112. Archive 112 provides for the storage and retrieval of images andreports. Workstations 121 . . . 129 provide for interpreting andreviewing images in archive 112. In some embodiments, a secured networkis used for the transmission of patient information between thecomponents of the system. In some embodiments, workstations 121 . . .129 may be web-based viewers. PACS delivers timely and efficient accessto images, interpretations, and related data, eliminating the drawbacksof traditional film-based image retrieval, distribution, and display.

A PACS may handle images from various medical imaging instruments, suchas X-ray plain film (PF), ultrasound (US), magnetic resonance (MR),Nuclear Medicine imaging, positron emission tomography (PET), computedtomography (CT), endoscopy (ES), mammograms (MG), digital radiography(DR), computed radiography (CR), Histopathology, or ophthalmology.However, a PACS is not limited to a predetermined list of images, andsupports clinical areas beyond conventional sources of imaging such asradiology, cardiology, oncology, or gastroenterology.

Different users may have a different view into the overall PACS system.For example, while a radiologist may typically access a viewing station,a technologist may typically access a QA workstation.

In some implementations, the PACS Gateway 111 comprises a qualityassurance (QA) workstation. The QA workstation provides a checkpoint tomake sure patient demographics are correct as well as other importantattributes of a study. If the study information is correct the imagesare passed to the archive 112 for storage. The central storage device,archive 112, stores images and in some implementations, reports,measurements and other information that resides with the images.

Once images are stored to archive 112, they may be accessed from readingworkstations 121 . . . 129. The reading workstation is where aradiologist reviews the patient's study and formulates their diagnosis.In some implementations, a reporting package is tied to the readingworkstation to assist the radiologist with dictating a final report. Avariety of reporting systems may be integrated with the PACS, includingthose that rely upon traditional dictation. In some implementations, CDor DVD authoring software is included in workstations 121 . . . 129 toburn patient studies for distribution to patients or referringphysicians.

In some implementations, a PACS includes web-based interfaces forworkstations 121 . . . 129. Such web interfaces may be accessed via theinternet or a Wide Area Network (WAN). In some implementations,connection security is provided by a VPN (Virtual Private Network) orSSL (Secure Sockets Layer). The clients side software may compriseActiveX, JavaScript, or a Java Applet. PACS clients may also be fullapplications which utilize the full resources of the computer they areexecuting on outside of the web environment.

Communication within PACS is generally provided via Digital Imaging andCommunications in Medicine (DICOM). DICOM provides a standard forhandling, storing, printing, and transmitting information in medicalimaging. It includes a file format definition and a networkcommunications protocol. The communication protocol is an applicationprotocol that uses TCP/IP to communicate between systems. DICOM filescan be exchanged between two entities that are capable of receivingimage and patient data in DICOM format.

DICOM groups information into data sets. For example, a file containinga particular image, generally contains a patient ID within the file, sothat the image can never be separated from this information by mistake.A DICOM data object consists of a number of attributes, including itemssuch as name and patient ID, as well as a special attribute containingthe image pixel data. Thus, the main object has no header as such, butinstead comprises a list of attributes, including the pixel data. ADICOM object containing pixel data may correspond to a single image, ormay contain multiple frames, allowing storage of cine loops or othermulti-frame data. DICOM supports three- or four-dimensional dataencapsulated in a single DICOM object. Pixel data may be compressedusing a variety of standards, including JPEG, Lossless JPEG, JPEG 2000,and Run-length encoding (RLE). LZW (zip) compression may be used for thewhole data set or just the pixel data.

Referring to FIG. 2, an exemplary PACS image search and retrieval method200 is depicted. Communication with a PACS server, such as archive 112,is done through DICOM messages that that contain attributes tailored toeach request. At 201, a client, such as workstation 121, establishes anetwork connection to a PACS server. At 202, the client prepares a DICOMmessage, which may be a C-FIND, C-MOVE, C-GET, or C-STORE request. At203, the client fills in the DICOM message with the keys that should bematched. For example, to search by patient ID, a patient ID attribute isincluded. At 204, the client creates empty attributes for all the valuesthat are being requested from the server. For example, if the client isrequesting an image ID suitable for future retrieval of an image, itinclude an empty attribute for an image ID in the message. At 205, theclient send the message to the server. At 206, the server sends back tothe client a list of one or more response messages, each of whichincludes a list of DICOM attributes, populated with values for eachmatch.

An electronic health record (EHR), or electronic medical record (EMR),may refer to the systematized collection of patient and populationelectronically-stored health information in a digital format. Theserecords can be shared across different health care settings and mayextend beyond the information available in a PACS discussed above.Records may be shared through network-connected, enterprise-wideinformation systems or other information networks and exchanges. EHRsmay include a range of data, including demographics, medical history,medication and allergies, immunization status, laboratory test results,radiology images, vital signs, personal statistics like age and weight,and billing information.

EHR systems may be designed to store data and capture the state of apatient across time. In this way, the need to track down a patient'sprevious paper medical records is eliminated. In addition, an EHR systemmay assist in ensuring that data is accurate and legible. It may reducerisk of data replication as the data is centralized. Due to the digitalinformation being searchable, EMRs may be more effective when extractingmedical data for the examination of possible trends and long termchanges in a patient. Population-based studies of medical records mayalso be facilitated by the widespread adoption of EHRs and EMRs.

Health Level-7 or HL7 refers to a set of international standards fortransfer of clinical and administrative data between softwareapplications used by various healthcare providers. These standards focuson the application layer, which is layer 7 in the OSI model. Hospitalsand other healthcare provider organizations may have many differentcomputer systems used for everything from billing records to patienttracking. Ideally, all of these systems may communicate with each otherwhen they receive new information or when they wish to retrieveinformation, but adoption of such approaches is not widespread. Thesedata standards are meant to allow healthcare organizations to easilyshare clinical information. This ability to exchange information mayhelp to minimize variability in medical care and the tendency formedical care to be geographically isolated.

In various systems, connections between a PACS, Electronic MedicalRecord (EMR), Hospital Information System (HIS), Radiology InformationSystem (RIS), or report repository are provided. In this way, recordsand reports form the EMR may be ingested for analysis. For example, inaddition to ingesting and storing HL7 orders and results messages, ADTmessages may be used, or an EMR, RIS, or report repository may bequeried directly via product specific mechanisms. Such mechanismsinclude Fast Health Interoperability Resources (FHIR) for relevantclinical information. Clinical data may also be obtained via receipt ofvarious HL7 CDA documents such as a Continuity of Care Document (CCD).Various additional proprietary or site-customized query methods may alsobe employed in addition to the standard methods.

With reference now to FIG. 3 a method of adapting image displaycharacteristics is illustrated according to embodiments of the presentdisclosure. At 301, a request for an image is received. As describedabove, an image request may take a variety of forms. In someembodiments, the image request is received by a PACS system from aworkstation. At 302, one or more characteristic of the requested imageis determined. In some embodiments, the one or more characteristic isdetermined from metadata contained in the PACS system. In someembodiments, the one or more characteristic is determined from DICOMheaders. In some embodiments, the one or more image characteristic isdetermined by image analysis. In various embodiments, imagecharacteristics may include subject anatomy, exam type, make or model ofimaging equipment, modality, presence of a region of interest, averageluminosity of the image, or image resolution.

At 303, one or more user characteristic is determined. In someembodiments, the user characteristics are maintained in a data storeexternal to the PACS. However, it will be appreciated that a PACS may bemodified to include supplemental user profile information. In variousembodiments, user characteristics may include specialty, visual acuity,characteristics of the user's display, or user history.

At 304, a model is applied to determine one or more image transformationbased on the one or more image characteristic and the one or more usercharacteristic. In some embodiments, the model is a statistical model.In some embodiments, the statistical model is a regression model. Insome embodiments, the regression model is a linear regression model. Insome embodiments, the model is a generalized linear model. It will beappreciated that a variety of alternative models are suitable for useaccording to the present disclosure.

In some embodiments, the one or more image transformation includeswindow/level, color balance, zoom, crop, addition of text annotation,addition of arrow annotation, or addition of line annotation. Forexample, a given image may be zoomed to a region of interest, an arrowinserted, and the window/level adjusted based on modality. In variousembodiments, the image is provided to a user workstation along with thetransformation. In such embodiments, the transformations may be appliedat the workstation prior to display of the image. In some embodiments,the transformations are applied at the server side prior to sending theimage to the user for display.

In alternative embodiments, the user characteristics are not included inthe model, which then relies on the image characteristics alone.

At 305, any further user-applied image transformations are monitored. At306, the model is updated based on any user-applied imagetransformations. In this way, the model can be updated on an ongoingbasis and thus may learn from usage patterns.

Referring now to FIG. 4, a schematic of an example of a computing nodeis shown. Computing node 10 is only one example of a suitable computingnode and is not intended to suggest any limitation as to the scope ofuse or functionality of embodiments of the invention described herein.Regardless, computing node 10 is capable of being implemented and/orperforming any of the functionality set forth hereinabove.

In computing node 10 there is a computer system/server 12, which isoperational with numerous other general purpose or special purposecomputing system environments or configurations. Examples of well-knowncomputing systems, environments, and/or configurations that may besuitable for use with computer system/server 12 include, but are notlimited to, personal computer systems, server computer systems, thinclients, thick clients, handheld or laptop devices, multiprocessorsystems, microprocessor-based systems, set top boxes, programmableconsumer electronics, network PCs, minicomputer systems, mainframecomputer systems, and distributed cloud computing environments thatinclude any of the above systems or devices, and the like.

Computer system/server 12 may be described in the general context ofcomputer system-executable instructions, such as program modules, beingexecuted by a computer system. Generally, program modules may includeroutines, programs, objects, components, logic, data structures, and soon that perform particular tasks or implement particular abstract datatypes. Computer system/server 12 may be practiced in distributed cloudcomputing environments where tasks are performed by remote processingdevices that are linked through a communications network. In adistributed cloud computing environment, program modules may be locatedin both local and remote computer system storage media including memorystorage devices.

As shown in FIG. 4, computer system/server 12 in computing node 10 isshown in the form of a general-purpose computing device. The componentsof computer system/server 12 may include, but are not limited to, one ormore processors or processing units 16, a system memory 28, and a bus 18that couples various system components including system memory 28 toprocessor 16.

Bus 18 represents one or more of any of several types of bus structures,including a memory bus or memory controller, a peripheral bus, anaccelerated graphics port, and a processor or local bus using any of avariety of bus architectures. By way of example, and not limitation,such architectures include Industry Standard Architecture (ISA) bus,Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, VideoElectronics Standards Association (VESA) local bus, and PeripheralComponent Interconnect (PCI) bus.

Computer system/server 12 typically includes a variety of computersystem readable media. Such media may be any available media that isaccessible by computer system/server 12, and it includes both volatileand non-volatile media, removable and non-removable media.

System memory 28 can include computer system readable media in the formof volatile memory, such as random access memory (RAM) 30 and/or cachememory 32. Computer system/server 12 may further include otherremovable/non-removable, volatile/non-volatile computer system storagemedia. By way of example only, storage system 34 can be provided forreading from and writing to a non-removable, non-volatile magnetic media(not shown and typically called a “hard drive”). Although not shown, amagnetic disk drive for reading from and writing to a removable,non-volatile magnetic disk (e.g., a “floppy disk”), and an optical diskdrive for reading from or writing to a removable, non-volatile opticaldisk such as a CD-ROM, DVD-ROM or other optical media can be provided.In such instances, each can be connected to bus 18 by one or more datamedia interfaces. As will be further depicted and described below,memory 28 may include at least one program product having a set (e.g.,at least one) of program modules that are configured to carry out thefunctions of embodiments of the invention.

Program/utility 40, having a set (at least one) of program modules 42,may be stored in memory 28 by way of example, and not limitation, aswell as an operating system, one or more application programs, otherprogram modules, and program data. Each of the operating system, one ormore application programs, other program modules, and program data orsome combination thereof, may include an implementation of a networkingenvironment. Program modules 42 generally carry out the functions and/ormethodologies of embodiments of the invention as described herein.

Computer system/server 12 may also communicate with one or more externaldevices 14 such as a keyboard, a pointing device, a display 24, etc.;one or more devices that enable a user to interact with computersystem/server 12; and/or any devices (e.g., network card, modem, etc.)that enable computer system/server 12 to communicate with one or moreother computing devices. Such communication can occur via Input/Output(I/O) interfaces 22. Still yet, computer system/server 12 cancommunicate with one or more networks such as a local area network(LAN), a general wide area network (WAN), and/or a public network (e.g.,the Internet) via network adapter 20. As depicted, network adapter 20communicates with the other components of computer system/server 12 viabus 18. It should be understood that although not shown, other hardwareand/or software components could be used in conjunction with computersystem/server 12. Examples, include, but are not limited to: microcode,device drivers, redundant processing units, external disk drive arrays,RAID systems, tape drives, and data archival storage systems, etc.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the embodiments, the practical application or technicalimprovement over technologies found in the marketplace, or to enableothers of ordinary skill in the art to understand the embodimentsdisclosed herein.

What is claimed is:
 1. A method comprising: receiving a request from auser for an image; determining one or more characteristic of the image;determining one or more characteristic of the user; applying ageneralized linear model to the one or more characteristic of the imageand the one or more characteristic of the user to determine one or moreimage transformation; applying the one or more image transformation tothe image; and updating the generalized linear model based on anyuser-applied image transformations.
 2. The method of claim 1, whereindetermining the one or more characteristic of the image comprisesreading image metadata.
 3. The method of claim 1, wherein determiningthe one or more characteristic of the image comprises reading DICOMheaders.
 4. The method of claim 1, wherein the one or morecharacteristic of the image comprises subject anatomy, exam type, makeor model of imaging equipment, modality, presence of a region ofinterest, average luminosity of the image, or image resolution.
 5. Themethod of claim 1, wherein the one or more characteristic of the usercomprises specialty, visual acuity, characteristics of the user'sdisplay, or user history.
 6. The method of claim 1, wherein the one ormore image transformation comprises window/level, color balance, zoom,crop, addition of text annotation, addition of arrow annotation, oraddition of line annotation.
 7. A system comprising: an image store; anda computing node comprising a computer readable storage medium havingprogram instructions embodied therewith, the program instructionsexecutable by a processor of the computing node to cause the processorto perform a method comprising: receiving a request from a user for animage; determining one or more characteristic of the image; determiningone or more characteristic of the user; applying a generalized linearmodel to the one or more characteristic of the image and the one or morecharacteristic of the user to determine one or more imagetransformation; retrieving the image from the image store; applying theone or more image transformation to the image; and updating thegeneralized linear model based on any user-applied imagetransformations.
 8. The system of claim 7, wherein determining the oneor more characteristic of the image comprises reading image metadata. 9.The system of claim 7, wherein determining the one or morecharacteristic of the image comprises reading DICOM headers.
 10. Thesystem of claim 7, wherein the one or more characteristic of the imagecomprises subject anatomy, exam type, make or model of imagingequipment, modality, presence of a region of interest, averageluminosity of the image, or image resolution.
 11. The system of claim 7,wherein the one or more characteristic of the user comprises specialty,visual acuity, characteristics of the user's display, or user history.12. The system of claim 7, wherein the one or more image transformationcomprises window/level, color balance, zoom, crop, addition of textannotation, addition of arrow annotation, or addition of lineannotation.
 13. A computer program product for adapting image displaycharacteristics, the computer program product comprising a computerreadable storage medium having program instructions embodied therewith,the program instructions executable by a processor to cause theprocessor to perform a method comprising: receiving a request from auser for an image; determining one or more characteristic of the image;determining one or more characteristic of the user; applying ageneralized linear model to the one or more characteristic of the imageand the one or more characteristic of the user to determine one or moreimage transformation; applying the one or more image transformation tothe image; and updating the generalized linear model based on anyuser-applied image transformations.
 14. The computer program product ofclaim 13, wherein determining the one or more characteristic of theimage comprises reading image metadata.
 15. The computer program productof claim 13, wherein determining the one or more characteristic of theimage comprises reading DICOM headers.
 16. The computer program productof claim 13, wherein the one or more characteristic of the imagecomprises subject anatomy, exam type, make or model of imagingequipment, modality, presence of a region of interest, averageluminosity of the image, or image resolution.
 17. The computer programproduct of claim 13, wherein the one or more characteristic of the usercomprises specialty, visual acuity, characteristics of the user'sdisplay, or user history.
 18. The computer program product of claim 13,wherein the one or more image transformation comprises window/level,color balance, zoom, crop, addition of text annotation, addition ofarrow annotation, or addition of line annotation.